Method and apparatus for producing polyurethane foam
AssigneeSealed Air Corporation (US)
InventorNelson E. Malwitz
Life of this patent
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Abstract
A method and apparatus are disclosed for producing polyurethane foam without the assistance of any through-flow mixing device for the precursor components. Air or other safe gas is mixed with a polyol-containing precursor to form a froth, and the froth is directed in a stream via a dispenser into a free space at a first predetermined rate of flow. Liquid isocyanate-containing precursor is directed in a stream via a dispenser at a second predetermined rate of flow into the free space so as to contact and mingle with the stream of froth. The mixed components then fall together into a container where they react to form polyurethane foam. Mixing of the streams is facilitated by a target upon which the two streams impinge in close proximity to each other.
Claims18
A method of making polyurethane foam, comprising:
- forming a first liquid precursor into a froth having a void fraction ranging from about 6 percent to about 16 percent, said first liquid precursor comprising a polyol;
- next, directing a stream of the froth into a free space;
- and
- directing a stream of a second precursor comprising an isocyanate into the free space so as to contsct and mingle with the stream of froth in said free space without the assistance of a through-flow mixing chamber or device, the two streams being maintained separate from each other prior to being directed into the free space such that the streams first make contact and mingle with each other in the free space and thereby react to form a polyurethane foam at a flow rate ranging from about 1 to about 10 pounds per minute.
A method of making a polyurethane foam comprising:
- forming a polyol-containing precursor into a froth having a void fraction ranging from about 6 percent to about 16 percent;
- next, directing a stream of the froth into a free space and against a target disposed in the free space;
- and
- directing a stream of an isocyanate-containing precursor into a free space and against the target, said target providing a mechanical intervention upon which both streams impinge, the streams falling together from the target under the influence of gravity and mixing as they fall in said free space without the assistance of a through-flow mixing chamber or device, the two streams being maintained separate from each other prior to being directed into the free space such that the streams first make contact and mingle with each other in the free space, whereby the polyol-containing precursor and the isocyanate-containing precursor mix sufficiently and react to form a polyurethane foam at a flow rate ranging from about 1 to about 10 pounds per minute.
Dependencies are inferred from the claim text.